What Are the Functions of Astaxanthin?

Astaxanthin is a carotenoid, which is an organic pigment. It is classified as a xanthophyll, which is the class of yellow pigments. This makes it similar to the more commonly known beta carotene, but yet it is structurally different. It also exhibits different chemical and biological properties, which has prompted researchers to study the functions of this compound and determine its effects on various conditions.

Sources

• Astaxanthin is a naturally occurring red pigment found in several different microorganisms and organisms. It is found in some microalgae, including Haematococcus pulvialis. It is also found in some yeast, including Xanthophyllomyces dendrorhous. Astaxanthin is found in krill, shrimp, lobsters, salmon, trout and flamingos. Since mammals, including humans, cannot synthesis (produce) astaxanthin internally, they must ingest it as part of their diet.

Antioxidant

• Astaxanthin exhibits powerful antioxidant activity. Antioxidants combat the effects of oxidation, the chemical process in which one molecule or atom steals electrons from another thereby changing the chemical make-up of each. Oxidation occurs due to exogenous (outside the body) factors like the environment and endogenous (inside the body) factors like metabolic processes. Carotenoids, including astaxanthin, act as antioxidants in several ways.

Singlet Oxygen

• Astaxanthin is able to quench singlet oxygen. Singlet oxygen, though not a free radical, has a pair of electrons that spin in opposite directions. This makes it a very reactive, and therefore unstable, compound. Astaxanthin has the ability to absorb the energy of the singlet oxygen, relaxing it to its ground (and therefore stable) state and then dissipating it as heat without ever changing its own chemical structure.

Free Radicals

• Free radicals are molecules that have an unpaired electron and most of them are highly reactive and therefore unstable. Because they have an unpaired electron, they will react with other molecules to try to gain an electron, but this can damage lipids (fats), proteins and DNA. Astaxanthin can efficiently find and react with these free radicals while it remains stable.

Immunologic Responses

• In animal studies, researchers have found that astaxanthin has the ability to enhance the production of antibodies. It can affect T-cells and T-helper cells and enhance immunoglobulin levels. Research in this area is still being conducted to determine how astaxanthin can be used to benefit various health conditions.

Anti-Carcinogens

• Studies in animals including mice and rats suggest that astaxanthin may be effective in the prevention of cancers. When animals were fed carcinogens (cancer causing agents) along with astaxanthin there was a reduced rate of cancer than in those animals fed only the carcinogens. This function of astaxanthin requires further research but provides a promising future.

Conditions

• With the various biologic responses astaxanthin evokes, there are many conditions that can benefit from supplementation with astaxanthin.
  Macular degeneration and cataracts, both usually brought on through the process of aging, are linked to the cumulative effects of light-induced oxidation. Astaxanthin and other carotenoids are able to reduce the risk of both conditions.
  Coronary artery disease occurs due to atherosclerosis, which is when plaque builds up in the arteries. It is believed that the oxidation of the low-density lipoprotein (LDL) is what contributes to atherosclerosis. Therefore it may be possible that antioxidants like astaxanthin can reduce the risk of coronary artery disease.
  There is evidence that oxidative stress is a factor in neurodegenerative diseases like Parkinson's disease and Alzheimer's disease. Research is being conducted to determine the ability of antioxidants in protecting nervous tissue from damage.